Dual DC magnetron cathode co-deposition of (Al,Ti) and (Al,Ti,N) thin films with controlled depth composition

Abstract

In this work (Al,Ti) and (Al,Ti,N) films with composition gradient in depth starting either with pure Al or pure Ti were deposited on Si, glass and Au at room temperature in a DC magnetron discharge without bias. The plasma parameters, for both custom made cathodes, were determined and the process was real-time controlled to obtain in the plasma the necessary deposition changes in relative metal abundances to get the desired depth profile composition on the films. In this work the process was designed to get a constant gradient for the composition depth profile. The morphology of the films was analysed by SEM while the composition gradients were measured by SIMS, XPS and RBS, confirming preset nominal depth composition profile of the films. To obtain (Al,Ti,N) thin films with gradient depth composition, N 2 must be supplied to the discharges. The plasma behaviour is modified in the presence of N 2 and the influence on the film characteristics is studied using the same techniques referred above. The (Al,Ti) and (Al,Ti,N) film properties are compared. We succeed in validating the coating technique opening new application possibilities.